Common technical parameters and calculation methods for coating coating

01 The volume solids of a coating
the volume solids of a coating, i.e. the volume ratio of non-volatile components of the coating to liquid paint. This is a very important concept, after the solvent in the liquid coating evaporates, what really remains on the surface of the coating to become the paint film is the non-volatile part of the coating, that is, the solid part.
examples: a paint product, measured its wet film thickness of 200um, dry film thickness of 80um, calculated its volume solids: volume solids sub-dry film thickness / wet film thickness of 80/200 - 40%
that is, the volume of the coating product solids divided into 40% .
02 dry film thickness and wet film thickness
the thickness of the dry film is usually specified in the coating contract. The determination of wet film thickness can help determine how thick coating layer must be constructed in order to achieve the required dry film thickness. The determination of wet film is conducive to the timely detection of differences in thickness of each construction coating in order to correct.
the known dry film thickness, check the volume solid content of the relevant products, calculate the corresponding wet film thickness, can be calculated according to the following formula.
examples: epoxy universal primer volume solid content of 57%, dry film thickness of 50 microns, the calculation of the wet film thickness to be constructed to meet the requirements.
film thickness, dry film thickness/volume solids, 50/57, 87.7≈90um.
03 Diluted wet film thickness
In actual construction, it is often necessary to add thinners to the coating, the use of thinners increases the total volume, but does not increase the volume solid content. For example, the addition of 25% diluent dilution coating, all that is needed is to add 25% figure in the formula, calculate the thickness of the diluted coating wet film, according to the following formula:
cases: solid content of 50% paint, dilution of 20%, to construct a thickness of 100um dry film. In order to ensure that the specified dry film thickness is achieved, what is the wet film thickness of the paint?
04 Theoretical coating rate
is a key factor in calculating cost and coating usage for owners and contractors, and theoretical coating rate refers to the area M2 that coating can be coated for every 1L, in M2/L.
In accordance with this definition, we can obtain the following formula for calculating the coating rate of liquid paint
at any given dry film thickness (expressed in square meters/litre): According to this definition, we can obtain the following formula for calculating the coating rate of liquid paint at any given dry film thickness (Expressed by square meters/litre):
e.g.: inorganic zinc-rich primer volume solid content of 63%, the thickness of the dry film is 75um, the theoretical coating rate is calculated:
05 actual coating rate
The percentage of cloth rate minus loss is calculated as follows:
If the theoretical coating rate has been calculated, and the percentage loss of coating can be estimated, such as 40% loss, then according to the thickness of the previous inorganic zinc-rich primer 75 microns, theoretical coating Rate:
actual coating rate , theoretical coating rate (1-40%) , 8.4 (1-40%) , 5.04m2/L
In fact, this percentage of loss is uncertain Because the actual construction is affected by a variety of factors, construction methods, working techniques, the shape of the coating, the roughness of the surface, the working environment and the distribution of the paint film.
06 The actual amount of paint
the actual amount of paint is obtained on the basis of the actual coating rate, can be calculated according to the following formula: more than
formula (1-loss) is the loss factor.
examples: there is a tank inner wall 2000M2, spray volume solid content of 76% of the phenolic epoxy coating 2 channels, each 150 microns, estimated loss of 40%, calculate how much L to use phenolic epoxy coating.
Then 2 coatings to use a total of 658×2 x 1316L
07 paint price calculation
in the coating project quotation, paint manufacturers often use different paint products, or even if the paint products are the same and different volume content of the product to quote, and the price is different. Can it be said that the low price is the low cost? It has been proved that products with high volume content, even if the unit price is high, the unit price per square meter is often lower than those with low price and low volume content of the product may also be less expensive.
examples: a structure, the construction of dry film thickness of 120 micron epoxy primer, the solid content of traditional epoxy primer is 50%, if the unit price is 32 yuan / L, high solid content modified epoxy primer solid content is 80%, if the unit price is 49 yuan / L, from which it can be seen that the use of high solid content modified epoxy primer, per square meter unit price is lower.
Foreign paint companies in the paint formulation design and technical data calculation and packaging specifications, are using the concept of L, domestic companies often use KG to calculate and package technical data, the introduction of the concept of quality can be convenient to calculate, the density of relevant data products can be derived from the manufacturer's data sheet.
three price per litre÷ density -
cases per kg price: a certain epoxy de-iron intermediate paint, density of 1.8KG/L, the price of 48.8 yuan/L, then the epoxy de-iron intermediate paint per kg price of 48 .8÷1.8 x 27.11 yuan/KG
Because the density of the coating is usually higher than 1.0KG/L, unless the solvent's thinner is sometimes lower than 1.0KG/L, the price per L is greater than the price per KG.